On my 67 Mustang's hood I bolted on a fiberglass hood scoop for a 69 Mach/68 428CJ. Between the scoop and hood there is a small uneven gap from the fiberglass not being perfectly straight. I can't even capture the gap well in a picture. The largest gap opening is probably larger than a 1/16" but less than 1/8". I could live with the gap, but it'd be a lot cleaner if I could eliminate it.

I use PlioGrip 2k seam sealer, I think #6. Is there any reason I couldn't just seal that gap up with this?

69 widetrack

04-07-2013 09:11 PM

I wouldn't use seam sealer on an outside visible area, especially the hood...why not take it off and build it up with fiberglass and work it until it fits the hood perfectly?

Ray

MARTINSR

04-07-2013 10:38 PM

Quote:

Originally Posted by 69 widetrack
(Post 1664047)

I wouldn't use seam sealer on an outside visible area, especially the hood...why not take it off and build it up with fiberglass and work it until it fits the hood perfectly?

Ray

X2

Brian

Lizer

04-09-2013 05:12 PM

I had considered that route, but don't see a way where I could do it and make it look good, and knew that would be a frustrating can of worms to break into.

Is advisement against the seam sealer aesthetic or were there functional reasons? It's sandable.

sedanbob

04-09-2013 08:32 PM

It seems like you could use something like a business card like a feeler gauge to identify where you need to remove material from the bottom of the scoop - if the card can't slide in, mark that spot for shaving. Use a long sanding board to keep it even. Measure, take a little off, measure again, and repeat until you get a snug fit. You will be removing less than 1/8".

69 widetrack

04-09-2013 08:58 PM

That's good advice Bob, if the scoop is built in a way that it could be shaved that would be an alternative to building it up, like you said, it's 1/8th of an inch at the most.

I wouldn't recommend seam sealer for both aesthetics and function. Aesthetics aside, the hood is an area that has movement (opening and closing the hood, vibration etc.) also you've got heat from from the sun and the engine, at night you've got heat from the engine, I can see it failing. If it does fail, now you need to repaint the hood and the scoop...and probably make it fit right.

Ray

Lizer

04-09-2013 09:07 PM

Good idea, yes the scoop is fiberglass and the outside edge can be sanded down quite easily.

Those are all good reasons, Widetrack. I didn't want to completely conceal the gap if I didn't have to because I personally like the look of a bolt-on hood scoop rather than the 'one-piece' look. I think that looks a little too 'clean.'

tech69

04-09-2013 09:08 PM

do whatever you can to find where it needs to be shaved and use a long block and 80-180. I'm doing something like that on my Mustang for the fender/quarter extensions. I walk up to the car and hold it in place where it's supposed to be, mark where it's touching and not allowing other places to touch, run to the vise which has my file in it, file for a couple minutes, and then run back to the car and re-check fit. The fender extension was so bad I questioned whether or not it was even for a 65, but after some filing and hitting it with a rubber mallet here and there it fits perfect.

Emphasis on using a block. :)

sedanbob

04-09-2013 09:24 PM

Quote:

Originally Posted by tech69
(Post 1664722)

do whatever you can to find where it needs to be shaved and use a long block and 80-180. I'm doing something like that on my Mustang for the fender/quarter extensions. I walk up to the car and hold it in place where it's supposed to be, mark where it's touching and not allowing other places to touch, run to the vise which has my file in it, file for a couple minutes, and then run back to the car and re-check fit. The fender extension was so bad I questioned whether or not it was even for a 65, but after some filing and hitting it with a rubber mallet here and there it fits perfect.

Emphasis on using a block. :)

I thought you were going to say "Emphasis on using the mallet"! ;)

tech69

04-09-2013 09:29 PM

that's only if Plan A doesn't work.

Lizer

04-13-2013 06:44 PM

I shaved it tonight and now it's much better. There are two spots....the very front points on the sides and the very rear corner...where the fiberglass is just too high and if I were to sand it so it's even I'd be sanding off a lot...prob more than 1/8". I bet I could slide a paint stick under these two areas.

How I could I build these parts of the scoop 'down?' I have polyester resin that you'd use with glass cloth. I'm trying to figure out how I could goo that on these areas, maybe gooing more on after it sets to build where I need it, then sanding to form.

MARTINSR

04-13-2013 06:49 PM

I can't see exactly where you are working but usually something like that would be done on the inside. Sand the surface where it is low on the inside. Put some tape on the outside as a "mould" to hold the resin from going all over the place. Apply some resin, put small pieces of mat there pushing it into the resin you brushed on with the brush and apply a little more resin and put another piece doing the same to push the air out of the matt or cloth what ever you are using. Let it go up much higher than you need and after it cures you remove the tape and sand the edge down to where you need it.

Brian

sedanbob

04-13-2013 07:48 PM

If you cover the hood with aluminum foil, then apply a coat or two of wax to the foil, you can set the scoop on top, then work some resin and some shreds of mat into the gap where it's too high. You are using the hood as the bottom of your 'mold'. When the resin sets up, pull the scoop off the hood, then sand the edges smooth, being careful not to sand the surface where it will join the hood. The foil keeps it from bonding to the hood. This would be a place where you could use some of the short-strand body filler ('kitty hair'). Regular body filler would chip off the edge.

MARTINSR

04-13-2013 08:01 PM

2X what Bob said, using a fiberglass reinforced filler makes a lot more sense.

Brian

Lizer

04-14-2013 12:00 AM

I don't find my fiberglass filler very easy to work. It didn't strike me as something that would have been good for such a small area like that.